3Com Switch 7750 Configuration Guide Guide

Voice VLAN Overview 101
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CAUTION:
■ If the voice stream transmitted by an IP voice device is with VLAN tag and the
port which the IP voice device is attached to is enabled with 802.1x
authentication and 802.1x guest VLAN assign different VLAN IDs for the voice
VLAN, the default VLAN of the port, and the 802.1x guest VLAN to ensure the
two functions to operate properly.
■ If the voice stream transmitted by the IP voice device is without VLAN tag, the
default VLAN of the port which the IP voice device is attached can only be
configured as a voice VLAN for the voice VLAN function to take effect. In this
case, 802.1x authentication is unavailable.
Manual mode
Tagged voice stream
Access Not supported
Trunk
Supported
Make sure the default
VLAN of the port
exists and is not a
voice VLAN. And the
access port permits
the packets of the
default VLAN.
Hybrid
Supported
Make sure the default
VLAN of the port
exists and is in the list
of the tagged VLANs
whose packets are
permitted by the
access port.
Untagged voice
stream
Access
Supported
Make sure the default
VLAN of the port is a
voice VLAN.
Trunk
Supported
Make sure the default
VLAN of the port is a
voice VLAN and the
port permits the
packets of the VLAN.
Hybrid
Supported
Make sure the default
VLAN of the port is a
voice VLAN and is in
the list of untagged
VLANs whose packets
are permitted by the
port.
Table 50 Matching relationship between port modes and voice stream types
Port voice VLAN
mode
Voice stream type Port type Supported or not